Research In Motion investors are turning skittish ahead of Wednesday’s critical launch of the company’s much-delayed new BlackBerrys.

THE SPARK: The sell-off in RIM shares this week follows a months-long rally. The company’s stock had nearly tripled from a nine-year low in September after favorable reviews on blogs and financial analysts started to see some possibility of a comeback.

THE BIG PICTURE: The BlackBerry, pioneered in 1999, has been the dominant smartphone for on-the-go business people and had also crossed over to consumers.

But the iPhone’s debut in 2007 showed that phones can do much more than email and phone calls, and exploded RIM’s market. The company’s shares sank for years as the BlackBerry lost ground to the iPhone and phones running Google Inc.’s Android system.

Now RIM promises to unveil a new operating system to catch up. Chief Executive Thorsten Heins will show off the first phone with the new BlackBerry 10 system in New York on Wednesday.

THE ANALYSIS: But doubts remain about the ability of BlackBerry 10 to rescue RIM.

“We’ll see if they can reclaim their glory. My sense is that it will be a phone that everyone says good things about but not as many people buy,” said BGC Financial analyst Colin Gillis. He said he wondered how many would ultimately sell and how profitable the new phones would be for RIM.

“We don’t know how successful it will be,” said Gareth Watson, vice-president of investment management and research at Richardson GMP Ltd.

Moreover, RIM is initially releasing only a touchscreen version of the phone, but Gillis said that the company should release a keyboard version at the same time. RIM has said it will release a version with a physical keyboard soon after the touchscreen model launch.

“You have 80 million subscribers and the No. 1 feature that they like is the physical keyboard,” Gillis said.

SHARE ACTION: Down 83 cents, or 5.1 percent, to $15.35 in afternoon trading on the Nasdaq. Shares dropped 7.8 percent on Monday. But in the four weeks through Friday, shares had gained 47 percent.